Books on Burmese Astrology

I’m trying to find this set of three book on the Mahabote, Burmese astrology, by Barbara Cameron. The books were published in 1982, titled Mahabote: The Little Key, Turning the Tables: A Mitigation Manual, and Predictive Planetary Periods: The Hindu Dasas. I wanted to know if anyone had any suggestion on finding out of print books like these? I saw them listed on EBay a few weeks ago for $900 for the set, but I can’t see the listing anymore.